Automatgenererad bild.

Fotograf: Bent Christensen

Published

17 March 2013

Fearless medicated perch of worldwide fame

In a new, acclaimed study, researchers have demonstrated behavioural changes in fish receiving low doses of an anxiolytic drug. Jerker Fick, a member of the MistraPharma team, is one of the researchers behind this study, which rapidly became a global news item.

Many of the drugs we ingest pass through the body and are flushed down the drain. Several of the substances these drugs contain cannot be removed by present-day wastewater treatment methods, and they therefore enter the environment. One pharmaceutical substance dispersed in this way is the drug Oxazepam, an anxiolytic (used to dampen anxiety in humans). A few researchers at Umeå University became curious about whether it might affect fish.

Jerker Fick, one of the researchers involved in the study, relates that they administered doses of Oxazepam to perch in large aquaria and studied what happened.

‘The strength and clarity of the effect was truly astonishing. Perch are normally shy and forage in shoals, but the ones given Oxazepam took more risks and swam off on their own to find more food.’

Effect even at low doses

This is the first time anyone has been able to demonstrate behavioural modification in this way and, what is more, with Oxazepam in concentrations as low as those found in Swedish watercourses. The study was repeated several times to ensure that the results were entirely reliable, and published in Science at the beginning of February. But the story does not end there.

‘One day,’ Fick relates, ‘they called from the journal and invited us to join them at the annual AAAS meeting, since there was such a lot of interest. We were tremendously pleased just that the article had been accepted in Science, and the most we’d thought of was that interest in the research might be enough for us to hold an internal seminar at home, at our university.’

The conferences arranged by the American Association for the Advancement of Science (AAAS) are among the world’s absolute largest scientific gatherings. Jerker Fick and his colleague Tomas Brodin flew over for the annual meeting held in Boston in mid-February, and told the assembled pressmen from all over the world about the surprising alterations in the behaviour of perch and possible effects on the ecological balance.

‘The big American news bureau Associated Press quickly got the news out, and the following day we were on the front page of the Washington Post and several other major newspapers. It felt truly unreal.’

Countless interviews for world press

After that, news of the perch and their personality changes spread fast in the US and beyond. Jerker Fick describes how unbelievably hectic the weeks since the meeting have been. Fick himself has been interviewed numerous times by Swedish and foreign journalists alike, and the principal author Thomas Brodin has undergone some 50 interviews.

Fick, also a participant in the MistraPharma programme, explains that although the study was not part of the programme it shows that MistraPharma’s basic concept is correct. Low concentrations of the biologically active pharmaceutical substances involved may be enough to have distinct environmental effects.

MistraPharma is now in its second phase and, besides surveying the spread of various pharmaceuticals, its researchers are also developing methods of capturing these substances in sewage treatment plants.

‘One substance the programme is looking at is Oxazepam, so the hope is that this research will solve the problem of it ending up in the environment,’ says Jerker Fick.

Text: Andreas Nilsson, Vetenskapsjournalisterna

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